Curing agent for low-emission epoxy resin compositions

Abstract

A curing agent for epoxy resin compositions containing at least one amine of formula (I) and at least one amine of formula (II). The curing agent is a low-odor, low-viscosity, low-toxicity curing agent and has a low propensity for carbamatization and a high reactivity toward epoxy resins. It enables low-odor and low-emission epoxy resin products which are readily processable and which even at low temperatures and high humidities undergo rapid and problem-free curing to afford high-quality plastics having a high hardness and a regular, non-tacky surface with high gloss.

The invention claimed is: 
     
       1. An epoxy resin composition comprising:
 a resin component comprising at least one epoxy resin and 
 a hardener component comprising a hardener for curing the at least one epoxy resin, 
 wherein the hardener comprises: 
 at least one amine of formula (I): 
 
       
         
           
           
               
               
           
         
         where 
         A 1  is an alkylene radical having 2 to 15 carbon atoms, A 1  optionally contains cycloalkyl or aryl rings, A 1  optionally contains ether oxygen or amine nitrogen, and A 1  is not 1,2-propylene, 
         R 1  is hydrogen, an alkyl radical having 1 to 8 carbon atoms or a phenyl radical, 
         X is an alkenyl radical having 2 to 18 carbon atoms, 
         m is 1, and 
         n is 1; and 
         at least one amine of formula (II): 
       
       
         
           
           
               
               
           
         
         where 
         A 2  is 1,2-ethylene or 1,2-propylene, 
         R 2  is hydrogen, and 
         Q is phenyl, 
         wherein the at least one amine of formula (I) is present in an amount such that 15% to 80% of a total amine hydrogens in the hardener originate from the at least one amine of formula (I), and 
         the at least one amine of formula (II) is present in an amount such that 20% to 50% of the total amine hydrogens in the hardener originate from the at least one amine of formula (II). 
       
     
     
       2. The epoxy resin composition as claimed in  claim 1 , wherein A 1  is selected from the group consisting of 1,2-ethylene, 1,3-propylene, 2-methyl-1,5-pentylene, 1,6-hexylene, 2,2(4),4-trimethyl-1,6-hexylene, 1,3-cyclohexylenebis(methylene), 1,3-phenylenebis(methylene), (1,5,5-trimethylcyclohexan-1-yl)methane-1,3, 3-aza-1,5-pentylene, 3,6-diaza-1,8-octylene, 3,6,9-triaza-1,11-undecylene, 4-aza-1,7-heptylene, 3-aza-1,6-hexylene, 4,7-diaza-1,10-decylene, and 7-aza-1,13-tridecylene. 
     
     
       3. The epoxy resin composition as claimed in  claim 1 , wherein X is selected from the group consisting of pentadeca-8-enyl, pentadeca-8,11-dienyl, and pentadeca-8,11,14-trienyl. 
     
     
       4. The epoxy resin composition as claimed in  claim 1 , wherein X is selected from the group consisting of pentadeca-8-enyl, pentadeca-8,11-dienyl, and pentadeca-8,11,14-trienyl, and where the X radical is in the 3 position and the amine-containing radical associated with variable n is in the 2, 4 or 6 position, based on the phenolic OH. 
     
     
       5. The epoxy resin composition as claimed in  claim 1 , wherein the amine of formula (I) is a reaction product of a reaction (i) or (iii):
 (i) reaction of
 a primary diamine of formula (III)
   NH 2 -A 1 -NH 2   (III)
 
 
 an aldehyde of formula (IV) 
 
 
       
         
           
           
               
               
           
         
         
           and a phenol compound of formula (V) 
         
       
       
         
           
           
               
               
           
         
         with elimination of water, and 
         (iii) reaction of
 a primary diamine of formula (III)
   NH 2 -A 1 -NH 2   (III)
 
 
 an aldehyde or ketone of formula (VII) 
 
       
       
         
           
           
               
               
           
         
         
           and hydrogen, 
         
         with elimination of water. 
       
     
     
       6. The epoxy resin composition as claimed in  claim 1 , wherein A 1  is an alkylene radical having 2 to 15 carbon atoms and contains an aryl ring. 
     
     
       7. The epoxy resin composition as claimed in  claim 1 , wherein A 1  is 1,3-phenylenebis(methylene). 
     
     
       8. The epoxy resin composition as claimed in  claim 1 , wherein R 1  is hydrogen. 
     
     
       9. The epoxy resin composition as claimed in  claim 1 , wherein the at least one amine of formula (I) is present in an amount such that 20% to 80% of a total amine hydrogens in the hardener originate from the at least one amine of formula (I). 
     
     
       10. The epoxy resin composition as claimed in  claim 1 , wherein A 2  is 1,2-propylene. 
     
     
       11. The epoxy resin composition as claimed in  claim 1 , wherein the amine of formula (II) is a reaction product of the reductive alkylation of ethylene-1,2-diamine or propylene-1,2-diamine with an aldehyde or ketone of formula (VIII) and hydrogen 
       
         
           
           
               
               
           
         
       
     
     
       12. The epoxy resin composition as claimed in  claim 1 , wherein A 2  is 1,2-ethylene. 
     
     
       13. The epoxy resin composition as claimed in  claim 1 , wherein the hardener component further comprises at least one further amine that does not correspond to formulas (I) and (II) and/or at least one accelerator. 
     
     
       14. A cured composition obtained from curing the epoxy resin composition as claimed in  claim 1 . 
     
     
       15. A coating comprising the epoxy resin composition as described in  claim 1 . 
     
     
       16. A cured composition obtained from curing the coating as claimed in  claim 15 .